Friday, November 23, 2012

Ný grein um dreifingu H2S frá jarðvarmavirkjunum

Ný grein um dreifingu H2S frá jarðvarmavirkjunum í nágrenni Reykjavíkur og veðuraðstæður sem valda því að styrkurinn nær yfir 50 µg/m3.

Throstur Thorsteinsson, Julia Hackenbruch, Einar Sveinbjörnsson, Thorsteinn Jóhannsson. 2013. Statistical assessment and modeling of the effects of weather conditions on H2S plume dispersal from Icelandic geothermal power plants. Geothermics 45: 31 - 40.

Greinin á síðu útgefandans Geothermics

Abstract

Episodes of high atmospheric load of hydrogen sulfide (H2S), where the concentration is over 50 μg m−3hourly average value, occur about 80 times a year in Reykjavik (data from 2007 to 2009). H2S originates mainly from two geothermal power plants 25–30 km (south-)east of Reykjavik, at Hellisheidi and Nesjavellir. Certain weather-dependent dispersion conditions, such as wind, cloud cover and air temperature, allow the transport of emissions towards Reykjavik and the neighboring cities, causing local air pollution. High concentrations of H2S occur within a narrow range of weather conditions, namely slow (mean value 2 ± 1 m s−1) easterly (114° ± 23°) winds, together with cold air temperatures (median value −3 °C) and preferably no, or little, cloud cover. A classification of weather types shows the preferred occurrence of high H2S concentrations in connection with low atmospheric exchange and autochthonous weather. Stable atmospheric stratification and inversions enable the transport of H2S emissions to Reykjavik. The measured concentrations, the short lived peaks in concentration and different values at nearby measurement stations, indicate a very narrow plume, which fits well with a Gaussian plume distribution model.

Thursday, November 1, 2012

Sand / ösku fok og há gildi PM10 á Raufarfelli

Mjög hár styrkur PM10 mælist á Raufarfelli.

20121101_Raufarfell_PM10

Styrkur svifryksmengunar, PM10, náði yfir 900 µg/m3 í dag, 1. nóvember, 2012 (gögn af mælivef VISTA).

Vindhraðinn hefur verið mikill, eins og gögn frá Kvískerjum sýna.

20121101_Kvisker_Vindur_IMO

Og á gervitunglamynd frá 13:40 í dag má sjá að það blæs sandi og ösku af öllu suðurlandi (MODIS NASA/Rapidfire).

20121101_modis_1340_crop